Stop mechanism for knitting machines



Jan.5,1937. TER AL 2,067,146

STOP MECHANISM FOR KNITTING MACHINES Filed March 15, 1936 3 Sheets-Sheet 1 WITNESSES: INVENTORS:

5Q mmm WPorMr & y John Wfiashom,

W a. W W

TORNEYS.

ifia w Jan. 5, 1937. H..W. PORTER ET AL 2,067,145

STOP MECHANISM FOR KNITTING MACHINES Filed March 13, 1936 3 Sheets-Sheet 2 FIG. 11. M 0 a INVENTORS: Harold WPorZsr A. y John Wfmsham,

Jan, 5,1937. H. w. PORTER ET AL 2,067,146

STOP MECHANISM FOR KNITTING MACHINES Filed March 15, 1936- 3 Sheets-Sheet 5 FIG M- WITNESSES: 1 N V EN TORS imrold TIC/ oria Z; y WBH/Sh/QT'E I W A?%RNEYS.

Patented Jan. 5, 1937 UNITED STATES PATENT OFFICE STOP MECHANISM FOR KNITTING MACHINES vania Application March 13, 1936, Serial No. 68,624 4 Claims. (Cl. 66-157) This invention relates to stop mechanisms for knitting machines, particularly flat knitting machines of the cotton type such as are used in the manufacture of fashioned hosiery and similar articles.

In knitting machines 'of the kind specifically referred to, the knitting yarn is laid crosswise of the thread notches of the sinkers and intervening dividers, by a reciprocating carrier at a time when said sinkers and dividers are in retracted position. As the yarn is laid, the sinkers are progressively advanced concurrently with the travel of the yarn carrier by action of the slur cock of themachine, and depress the yarn in the intervals between adjacent pairs of the needles, whereupon the dividers are advanced en masse by the catch bar of the machine to apportion the yarn evenly amongst all the needles, the loops thus formed being incorporated with 20 the fabric being knitted through manipulation of the needles in a well known manner. After the feeding of yarn for each course of the knitting, the sinkers and the dividers are concurrently retracted en masse in readiness for the laying of yarn for the succeeding course of the knitting, thisbeing also efiected by the catch bar which is provided with a longitudinal groove for engaging the butts respectively of said sinkers and dividers. If, for any reason, the catch 30 bar should be abnormally lifted clear of the divider butts or be prevented from moving down with the lifting member therefor to engage the sinker butts and thus fail to retract the sinkers and dividers from their yarn sinking position, said sinkers and dividers will be left in the path of the thread carrier. Accordingly, upon the ensuing actuation of the carrier, a smash will result with attendant injury to it as well as the sinkers and dividers, the correction for which difilculty is not only costly from the standpoint of parts replacement and labor, but entails idling of the knitting machine for a considerable period with corresponding curtailment in the production therefrom.

Our invention is directed in the main toward precluding such contingencies, which objective we realize in practice, as hereinafter more fully disclosed, through provision of means which is automatically operated in the event of relative movement between the catch bar and the lifting member therefor due to interference with the normal functioning of said bar, to automatically effect stoppage of the machine before the next actuation of the thread carrier or carriers.

Other objects and attendant advantages of this invention will appear from the following detailed description of the attached drawings, wherein Fig. I is a fragmentary view showing, in part, the cross section of a flat stocking knitting machine conveniently embodying our invention.

Fig. II is a view similar to Fig. I showing an abnormal condition where the sinkers are disaligned in respect to the dividers and the butts of the disaligned sinkers holding the catch bar raised relative to the lifting member therefor.

Fig. III is a view corresponding to Fig. II drawn to a somewhat larger scale.

Fig. IV is a detail sectional view of an electric switch forming a part of the stop mechanism.

Figs. V and VI are views similar to Fig. III showing a modified embodiment of our invention.

Figs. VII and VIII are like Figs. V and VI and show still another modification of our invention; and

Fig. IX is an exploded view of the component parts of a switch embodied in the modification of Figs VII and VIII.

Insofar as it is illustrated herein, the knitting machine proper is of well known construction and comprises a series of sinkers l which are arranged in alternation with dividers 2 in individual transverse guide grooves of the sinker head 3, said head being mounted on the longitudinal supporting rail 4 of the machine. The sinkers I are actuated as ordinarily by individually-associated pivoted jacks 5 which are subject to the influence of a slur cock 6 on a longitudinal slide bar I. As usual, the catch bar of the machine designated by the numeral 8 has a groove 9 for engaging the upstanding butts l0 and II of the sinkers and the dividers I and 2. Secured to thecatch bar 8 are rearward arms whereof one is shown at l2, said arm being pivotally connected at I3 to an upwardly reaching arm IE on a rock shaft I6, which latter, through another arm partly shown at I! is actuated by a suitable rotary cam (not illustrated) on the cam shaft of the knitting machine to impart the horizontal movements to the catch bar. To the catch bar 8 is also secured a forwardly projecting arm l8 with a socket aperture IS in its outer end engaged by the upper spherically headed end 26 of a lifting member or arm 2|, which, like the arm 11, is actuated by a suitable cam (not shown) on the cam shaft of the knitting machine. One of the yarn carriers of the machine is indicated at 22, and one of the needles at 23.

In the normal operation of the machine, the

. consequence of being arrested for example by the yarn carrier 22 is moved crosswise of the sinkers and dividers and 2', and lays the knitting yarninto the frontal notches or throats of the latter. Concurrently with the advance of the yarn carrier 22, the slur cock 6. in following, actuates the jacks 5 successively to progressively advance the sinkers When the carrier 22 has completed its traverse, the dividers 2 are advanced en masse through forward movement of the catch bar 8 to apportion the yarn previously measured bythe sinkers between the individual needles. The loops thus formed aboutthe shanks of the needies 22 are incorporated in the fabric being knit ted in the machine by actuation of the needles in a well known manner. Immediately after sinking and apportionment of the yarn for each course of the knitting, the lifting member2| moves downward and permits the catch bar 8 to engage the butts ll) of the sinkers in its groove 9. Thereupon, the catch bar 8 is'drawn leftward in Fig. I throughcounterclockwise actuation of the shifter arm l5 to concurrently'retract the sinkers and the dividers relative to the yamcarrier 22 and the -needles-23 in'readines's for laying of the yarn for the succeeding course of the knitting by traverse of the yarn carrier in the opposite direction. The machine in this instance is driven by a multiphase electric motor 'whichis conventionally represented at 25 in Figs. I and II, and which receives current from the three wire power line designated 26, 21, 28. By' means of push button switches 29, 3B, the motor 25 can be stopped and started at will as required at the completion of each knitting cycle to prepare the machine for the knitting of another set of stocking blanks, or as may be required during the knitting;

Coming now to the stop mechanismwith which the present invention is more especially concerned andstill referring to Figs. I-IV, the embodiment there shown'includes a control means in the form of a switch 3| which is secured by a clamp 32 to the lifting arm 2| at a point somewhat below the head 28 of the latter. The switch 3| may .be of a well known construction with a body. 33 of insulation from one end of-which projects'a pair of spring-urged plunger pins 34, 35. Normally, as shown in Fig. I, the plunger pins 34, 35 yieldingly engage a bridging contact piece 36 set intoa small block of insulation 31 secured to the forwardly projecting arm I8 on the catch bar 8. As shown, the switch 3| is in circuit with the coil of a-normally energized relay 38 connected across thephase 26, 21, of the power line, the current flowing. from the line wire, 26 to said relay coil through thev relay switch 39, the conductor 40, the}; pin 34 of the switch, 3|, the pin 35, the conductor 4|, the switch 30, and the conductor 42 to the line wire 21. In a manner later on explained, the relay 38 also actuates the triple motor switchindicated at 43, 44, 45.

With the arm l6 on the catch bar 8 engaged with the head 20 n the lifting member 2|, as shown in Fig. I, during normal functioning of the machine, the plunger pins 34 and 35 of the switch 3| are in contact with the bridging plate 36 on said arm |8 so that the circuit through the coil of the relay 38 is closed with current flowing from the line 26, 21, 28 to the motor 25. If, for some reason, the catch bar 8 should be prevented from descending with-its lifting arm 2| as a butts of sinkers disaligned relative to the dividers 2 as shownin Figs. II and III and ,thus not be permitted to retract the sinkers as ordiat any time and attendant opening of the motor switch 43,

44,45, as shown in Fig. II. The foregoing occurs as the catch bar 8 is being drawn rearward by a counterclockwise movement of the shifter arm l sothat an ample time interval is afforded for I stoppage of the machine before the yarn carrier rier 22 is prevented from fouling the non-retracted sinkers, with'preclusion of injury to it or said sinkers.

In the modified form of our invention shown in Fig. V, the switch 3|a is provided with spring prongs 34a'and 35min lieu of the spring-pressed plunger pins of the first described embodiment. The spring prongs 34a, 3512 are normally bridged by a contact band 360. set into a vertical bar 31a of insulation which issecured by a set screw 46 in a block 41 secured at the outer end of the arm -|8. The electrical connections for the modified form of switch 3|a in Fig. IV may be the same as those shown in Figs. I and II. By adjusting 224s again actuated. In this way, the yarn car-- the bar 31a infitheblock 41, the inset contact band 3611 may be so positioned as to close the switch 3|a whenrelative vertical'movement of element 2| takes place, while'non'nally said band occupies a level below the inward projections of the spring prongs 34a, a. Therefore, as arranged in Fig. V, the modified form of control the arm l8 on the catch-bar 8 and the lifting switch 3|a can be used in instances where the w switches for the electric drive-motor areactu 'ated by a normally de-energized relay.

In the modified form of our invention shown in form to fit'about the head 20 of the lifting in Figs. VII-IX, the control'switch 3|b comprises a body 33b of insulation which is made annular arm 2| whereto it is secured by means of a set screw 32b. Surmounting the switch body 33b is a flat annulus 48 of springy sheetmetal which is by a flat headed screw 34?; whereof the shank has metallic engagement with the end of the conductor b. The other end of the metallic annulus 48 is left free and is bent upwardly as shown at 36b in Fig. IXto serve as a springcontact in opposition to arounded head of another screw .35b whereof the shank engages a terminal socket 53 (Figs. VIIand VIII) for the conductor Mb set into the switch body 33b. When the arm l8 8 and the lifting arm 2| occupy the normal relation shown in Fig. VII with said arm |8 bearing upon and pressing down the annulus 50 of insulation,

the free spring end 36?) of the metallic annulus 48 is maintained in contact with the head of the screw 35? so that electric current may normally I flow through the conductors 40b and 4|b. However, upon relative movement between the parts H3 and 2| as shown in Fig. VIII, the spring end 36b-of the annulus 48 will move away from the head of the screw 35b to interrupt the flow of current between the conductors 40b, 4| b, the unattached portion of the ,ring of insulation 50 yielding to upward movement under the action of said-spring end. Obviously, the ring 50 serves toprevent short circuiting of the switch contacts by the arm I8.

It is of course to be understood that the switches 3|, 3| a and 3th are to be duplicated for the several knitting sections of the machine.

Having thus described our invention, we claim:

1. In a flat knitting machine comprising a series of needles, a corresponding series of sinkers, a reciprocating yarn carrier, a catch bar for withdrawing the sinkers relative to the needles after each yarn sinking operation, a lifting member on which the catch bar rests, and an electric motor for driving the machine; the combination of stop mechanism including a control switch carried by the lifting member operative upon failure of the catch bar to withdraw the sinkers as aforesaid, to effect interruption of current to the motor and, in turn, stoppage of the machine.

2. In a flat knitting machine comprising a series of needles, a corresponding series of sinkers', a reciprocating yarn carrier, a catch bar for withdrawing the sinkers relative to the needles after each yarn sinking operation, a lifting member upon which the catch bar rests, and an electric motor for driving the machine; the combination of stop mechanism including a switch means carried by the lifting member and actuated through relative up and down movement between the catch bar and said lifting member to effect interrupt-ion of the current flow to the motor, and, in turn, stoppage of the machine.

3. In a flat knitting machine comprising a series of needles, a corresponding series of sinkers, a reciprocating yarn carrier, a catch bar for withdrawing the sinkers relative to the needles and the yarn carrier after each yarn sinking operation, a lifting member upon which the catch bar rests, and an electric motor for driving the machine; the combination of stopmechanism including a switch with terminal contacts carried by the lifting member and normally bridged by an insulated plate on the catch bar, whereby, upon relative vertical movement between the catch bar and the lifting member said switch is opened to effect interruption of current flow to the motor, and, in turn, stoppage of the machine.

4. In a fiat knitting machine comprising a series of needles, 9. corresponding series of sinkers, a reciprocating yarn carrier, a catch bar for withdrawing the sinkers relative to the needles and the yarn carrier after each yarn sinking operation, a lifting member upon which the catch bar rests, and an electric motor for driving the machine; the combination of stop mechanism including a control switch for the motor having a body of insulation secured to the lifting member aforesaid, and a spring contact finger surmounted by a yielding protecting member of insulation, said contact finger being normally maintained in engagement with a contact on the switch body by 25 the protecting member under the weight of the catch bar, so that, upon relative vertical movement between said catch bar and the lifting member, the switch automatically opens to intcrrupt current flow to the motor and thereby stop the machine.

HAROLD W. PORTER.

JOHN W. BASHORE. 

